XOMA Corporation
(Nasdaq: XOMA), a leader in the discovery and development of therapeutic
antibodies, today announced preliminary top-line data from an interim analysis
of its Phase 2 proof-of-concept (POC) study to evaluate the safety and
efficacy of gevokizumab, a potent modulator of interleukin-1 beta (IL-1 beta),
for the treatment of the inflammatory facial lesions seen in patients with
moderate to severe acne vulgaris.

The Phase 2 POC study is a double-blind randomized comparison of gevokizumab
0.2mg/kg and 0.6mg/kg versus placebo given subcutaneously once per month for
three consecutive months. Investigators have enrolled a total of approximately
125 patients to date, and the interim results are based on up to 92 patients
with available data. In line with FDA guidance, inflammatory lesion counts,
the primary endpoint in this trial, and overall acne severity as assessed by
responder analysis of the Investigator Global Assessment (IGA), defined as at
least a two-point improvement on a five-point scale, were measured at
different time points up to Day 84. The study was designed to have 80 percent
power to detect at least an absolute difference of 15 versus placebo in the
mean inflammatory lesion count at Day 84 with statistical significance defined
as p≤ 0.10.

The 0.6mg/kg dose group showed a statistically significant reduction of 19 in
mean inflammatory lesion count on Day 42 compared to a reduction of 13 in the
placebo treated group (p=0.077). Each of the groups had a mean baseline of
approximately 31 inflammatory lesions. The magnitude of the difference was
substantially maintained throughout the study, but differences at later
measurement points were not statistically significant. The 0.6mg/kg dose group
demonstrated both a clinically and statistically significant improvement in
IGA at Day 84, showing a 31 percent responder rate versus a 5 percent
responder rate in the placebo group (p= 0.031). The 0.2mg/kg dose group showed
no clinically or statistically significant differences from placebo at any
time point in inflammatory lesion count or in IGA.

Gevokizumab appeared to be well tolerated in the trial, and incidence of
adverse events was comparable between both active groups and placebo. The
study was dosed in a mg/kg fashion with mean patient weights of approximately
74 kg, thus actively treated patients received mean absolute doses at the
0.2mg/kg and the 0.6mg/kg of around 15 mg and 45 mg respectively.